Stereographs are made using two lenses on the camera.  Two separate images are captured at the same moment from slightly off-set positions (like your eyes).  When viewed with a viewer or in some manner where the two images are merged (like cross-eyed) you get a sense of 3 dimensional-ness.  I eventually want to come up with a simple viewing method, like google cardboard, so that it is easy for people to see these.